Rhys Evans a

Claire Morgan b

Yamni Nigam c

a College of Human and Health Sciences, Swansea

University

b College of Medicine, Swansea University

c Lead Swansea University Maggot Research Group

Correspondence:685449@swansea.ac.uk

+44 1792 518565

Detection of Growth Factors in maggot secretions, and their possible role in

enhanced wound healing

Figure 1. Clinical used of larval debridement therapy. (A and B) Maggot infested wound (B) [1, 2] and (C) the adult stage of the common green bottle fly [3].

A B C

Chronic wounds can develop in a number of pathologies. Characterised by altered growth characteristics including an inability to heal, chronic

inflammation and infection unresponsive to antibiotics Larval debridement therapy (LDT) has been show to effectively treat chronic wounds Previous studies have show that the healing properties of maggot native excretions/secretions

(nES) may be due to the presence of digestive proteases [3,4].

Our Hypothesis:Additional factors are present in the maggot secretions which contribute to wound healing.

Our Research: Maggot secretions with and without protease inhibitors (PI) were added to human skin fibroblasts

and their effects measure using A) growth and B) migration assays.

Maggot secretions were analysed for human protein homologues by Western Blot technique.

Chronic Wounds

A B

Figure 2. The benefits of larval debridement therapy (LDT) in the treatment of chronic wounds such as Buerger's disease (A) and diabetic gangrene (B) [2].

Vehicle control nES with added PI

nES without PI

t0

t12

t14

t16

Effect of maggot secretions on cell migration

Figure 3. Fibroblast migration following treatment of nES with and without added protease inhibitors. Following treatment with maggot nES with added protease inhibitors, fibroblasts were found to migrate at a significantly faster rate across an artificially created wound compared to the vehicle control (P <0.05).

Figure 4. A – E are representative western blots demonstrating the presence or absence of proteins homologous to the human growth factors TGF-β (A), VEGF (B), EGF (C), FGF (D), PDGF (E) and HGF (F) detected in maggot secretions. Lane 1, MW ladder. Figures 1A, C-F: lane 2, positive control; Lane 3-6 nES (1 - 0.125 concentrated). Figures 1B: lane 2-4, positive cell control lysates (PC-3, PNT-2, LnCAP); Lane 5-8 nES.

Detection of human growth factor homologues in maggot secretions

1 2 3 4 5 6

1 2 3 4 5 6

1 2 3 4 5 6 7 8

1 2 3 4 5 6 1 2 3 4 5 6

1 2 3 4 5 6

Human TGF-β

Maggot secretions

Human EGF

Maggot secretions

Human PDGF-BB

Maggot secretions

Human VEGF

Maggot secretions

Human FGF

Maggot secretions

Human HGF

A B

C D

E F

Chronic wounds are a significant health issue and result in a massive financial burden on the NHS.

Maggot nES are able to significantly increase fibroblast migration but did not affect fibroblast migration.

Maggot secretions appear to possess human growth factor homologues which may contribute to the increased rate of wound healing see during LDT.

Conclusions

References1. http://missipipure.blogspot.co.uk/2010/07/lalat-dalam-kesehatan.html(accessed on 22/04/2015).2. http://imgarcade.com/1/maggot-therapy-for-wounds/ (accessed on 21/04/2015).3. http://www.agenciadenoticias.unal.edu.co/ndetalle/article/larvae-feed-on-dead-tissue-and-help-to-avoid-amputations.html

(accessed on 21/04/2015).4. http://www.btmcl.com/eng/ (accessed on 21/04/2015).5. Horobin A et al. Maggots and wound healing: an investigation of the effects of secretions from Lucilia sericata larvae upon

interactions between human dermal fibroblasts and extracellular matrix components. British Journal of Dermatology. 2003;148(5):923-33.

6. Horobin A et al. Maggots and wound healing: an investigation of the effects of secretions from Lucilia sericata larvae upon the migration of human dermal fibroblasts over a fibronectin-coated surface. Wound Repair Regeneration. 2005;13(4):422-33.